Sail



Feb. 10, 1931'. u LUDER 1,792,106

Filed May 23. 1930 Patented Fat. 10, 1931 ALFRED n. LUDER-S, or STAMFORD, CONNECTICUT SVAIL. 1

Application filed May 23,

This invention relates to sails for vessels and more particularly to a kind of sail known as a spinnaker, being a long approximately triangular sail frequently employed opposite r, a main sail on a yacht when it is sailing before the wind.

I have discovered that if I cause such a sail to materially 'distend intermediately, or bag toward the front and sidewise, I can 10 increase the effect of the wind thereon, and thereby increase the speed of the vessel. I prefer to effect the desired bagging by gathering the edges of the sail so that it does not naturally lie flat, but in a sort of pouch 1; form. To prevent such gathering from puckering the sail edges and interfering with the handling of the same, I first form V- shaped notches in the sail edges and then bring the sail cloth together on opposite sides 20 of such notches so that the perimeter or I boundary along the luff and leech and bottom of the sail is materially reduced over that of an ordinary sail of originally the same size. This causes the intermediate region of the 2." sail to bow forwardly and sidewise to a very decided extent.

lVhile I can make the V-shaped recesses in a sail as ordinarily constructedthat is, with different strips of cloth all' parallel to .m each other1 prefer to arrange the strips so that the seams are approximately at right angles to the luff, leech and bottom. Thus, the V-shaped notches are made at the ends of such seams, and then when the sewing of 5 the sail cloth is finally completed the sides of the V-notches come together to produce a continuation of the seam and a smooth fabric surface is produced but with a very materially reduced boundary and a pronounced'bagging. 40 My invention is hereinafter more fully explained in connection with the illustrations in the drawings, and the essential novel features are summarized in the claims.

In the drawings, Fig. 1 is a side elevation 4 of a sloop-yacht with my spinnaker set; Fig.

1330. Serial N5. 454,936.-

. 2 is a view 'of'the sail cloth of the spinnaker asoriginally cut and seamed, but before the sewing at thenotches is efiected; Fig. '3 is a view on the same scale of this spinnaker after the notches are brought together, illustrating the reduction in size by reason of the gathering together of the boundary edge; Figs. 4: and 5 are diagrams illustrating respectivelya longitudinal section and a transverse section of'the ordinary spinnaker'and of'my spinnaker having thesame amount of clothQ- j J In Fig. 1,'A indicates a suitable sloop-yacht having a mast B which is shown as carrying usual sails, as for instance main sailC, top sail D and balloon jib E attached at its lower end to the bow sprit F. In this figure G, indicates my spinnaker, which is attached at its upper end, at g, to the mast, and at one lower corner secured byja clew H. At the other'corner it is secured to a light spinnaker boom J- stepped onto the mast and held by a suitable sheet K, or set flying from a rope or sheet, dispensing with the spinnaker boom.

This view is somewhat conventional, but is intended to indicate the position of the spinnaker when the vesselds s'ailing befo're the wind,the direction of which is indicated by the'arrow. r f A i Fig. :2 indicates thesail cloth of my spin naker Gr before the edgesjare gathered; It will be seen there is a central longitudinal seam lOwhich extends from the top of the sail to a point 11 which is about equi-distant from the luff andleechjedges' and from the b'ot i passes as two miter seams 12'and l 3, leading from thepoint 11: to the point where the bot'- tom joins thelluif o'rj leechedge The inner ends of the fabric strips 15 terminate at the tom. From this point the seam divides and the outer edge, V-shaped notches 17 are made in registration with the seams 16. This gives a fabric structure in a plane of the form indicated in Fig. 2, and indicated in vertical and transverse section by the straight lines X and Y in Figs. 4 and 5.

Having formed the basis of the sail as above explained, I stitch together the opposite edges of each V-shaped notch, thus materially reducing the boundry 18 and bringing the sail'into the bag-like form shownin Fig. 3, this form being also indicated by the vertical and transverse sections Xl'and 'Ylrespectively in Figs. 4 and 5. Suitable hems, with or Without embedded cords, may be employed at the edges, as desired.

Experiments which I have made with a.

spinnaker produced as above described, show that such sail is more effective in driving the vessel than anordinary spinnaker. This advantage may be due to the fact that the bagshape retains the wind more effectively than heretofore, or. it may be that it is able to catch wind which is not directly from the stern, or it may be that when the bag fills with wind it presentsa greater area thereto than with the flat sail of the same perimeter. Apparently this arrangement also enables the top partof the sail to perform a greater proportion of the work than heretofore, and experience has demonstrated that the top portion is the most efhcient region of the, sail-in driving a vessel.

I claim 1-- 1. A substantially triangular sailhaving its edges periodically gatheredto materially.

reduce the boundary.

2. A sail made of fabric stripscstit'cheditogether and having notchesat its edgesgwhich are thereafter closed to reduce theboundary length of the sail.

3. A sail made of fabric strips stitched together and having inwardly pointing V.- shaped notches atits edges the boundaries of which are thereafter brought together to re duce the perimeter of the sail.

4. A sail having fabric strips stitched together by seams, which seams lead toward the boundary of the sail, the sides of the strips beingcut away at the boundary in, registra;

tion with the seams to provide V -shaped notches. which are thereafter closed.

5. A spinnaker made up of fabric strips extending at approximatelyrigh-t'angles to its luff, leech and bottom edges, the strips of' signature.

' ALFRED E. LUDERS. 

